Jig for forming closely-spaced holes



Sept. 23, 1930. G. w. BOOTH JIG FOR FORMING CLOSELY SPACED HOLES FiledOct. 6, 1926 3 Sheets$heet 1 INVENTOR La. 1% ATTORNEY Sept. 23, 1930.

G. W. BOOTH JIG FOR FORMING- CLOSELY SPACED HOLES Filed Oct. 6, 1926 3Sheets-Sheet 2 1NVENTOR L ATTORNEYS lllllllllllllllllllilullll Sept. 23,1930. G. w. BOOTH 77 JIG FOR FORMING CLOSELY SPACED HOLES Filed Oct. 6.1925 s Sheets-Sheet s INVENTOR 7-. l i a 4g ATTORN EY Pat hteel ,7 I

OF I

' GEQiRGEW: room, or snnrrmonng ARYrA'ivi),'nssrsivonfny' MEsNEassronmnnrs;

lro cnowirooax asnanoommnv, 1nd, or new ironic, N. Y., A conronnrron orThis invention relates to'ainethodiof and unwronx V JIG' roe-romaineorosntisrao'nn HOLES f i Application'filed October 6, 1926. Serial No.139,811;

I apparatus for formingvcloselyispaced holes in a ;plate or bar. I y 7 3In drillingholes in plates or "bars it has been found difficult to.obtain satisfactory results where the holes are close together andextreme accuracy is desired; For example, vwhen holes n a closely spacedseries are equal release of strains byren oval'offthe drilled one afteranother in a metal bar, the bar isjliable to vary after drilling duetoun 'metal; I Such varying, even though it may be lslight, is; ofimportance ;where extreme accuracy is desired,

. ,Furthenit has tering the drill." But iftheholes to be drilled areclosely spaced as in dies for perforating papersheets, the bushings haveto be so close,

together as topresent prohibitive practical difiiculties. Consequentb;under hitherto known methods of drilling the advantages 7 'ofguidebushings mustbe dispensed with."

It is an object of the present invention to provide a methodof andapparatus for forn ingiclosely spaced holes in a plate or bar with"extreme accuracy. More particularly, it -is anobj ect of theinventiontoprovide a neth od of, and-apparatus forformingholesin a plate or bar,such that danger of the plate or bar Warping is avoided, and such thatguide bushingsfor the drill may be utilized even :for very closelyspaced holes. I

1 With these general objects, and othersnot specifically referred to, inview,'the inven- E"gure. 1 1s a vlew, inside elevation, with parts invertical section, of apparatus con-j ;structed in accordance withtheinvention;

Figure '2 is a transverse vertical sectional view of the salne, withparts broken away; "yrigures is a top plan view of the same;

Fi ure/t is an end vi ew (of a stop element j .Figure 9. is a p a beenfound advantageous, I in dr lling plates and bars where accuracyis-desired, to utilize-guidebushings for cent Figures 5,6 and 7 aresideviews of sub; stitutestop elements; i

plementary dies for perforating vendless sheets; p l I a side view ofamale die;

Figure 10 is a sectionalview of thesame; Figure 11 is a side view of .afemale die;

Figure'12is a sectional viewof the same;

Referring to the drawings,.theinvention.

is illustrated in connection withthe formation of a row of'holes ina"bar,.such as a die bar. The dies illustrated as an exa'mple aredesigned particularly for perforating endless Figure 8 is a diagrammaticviewof conislieets,such as sheets of stamps. Thesheet is fedcontinuouslybetween rolls 21, 22 (Fig.

8) having radial slots inwhichthedies are mounted. Each male diecomprises along bar 23 having, on one side, a cutout groove 24 forreceiving an anchoring solder orceinenting material25. This bar carriesa row of perforating pins 26 spacedcl1osely together in accordance withthe desired perforations.

In the present embodiment, this spacing accordswith the perforations.ins'heet's of ordinary postage stamps. Thesepins are located in holes27 in the bar and are anchored therein by thecen enting material 25.Each female die comprises a somewhat similar bar 28l1av1ng a .cut awaygroove 29 alongone side thereof. This groove leaves, as appears in Fig.12, a-face flange30 and this flange is drilled with die holes 31closelyspaced in accordance withthe pins 26. The bars are ground toequal length and have gauging shoulders 32, 33. The present methodof'an'd apparatus for drilling holes is adapted for either the vfemaledies or forfthe holes that receivethe pins of the male dies. Figs, 13-16illustrate'the drilling of the holes for receiving the pins of the maledies and Figsl and 2 illustrate thedrillingjof the female dies.

In either case. the-end in viewjisa row of closely I and equally spacedholes and this spacing may be referred to, for'convenience,

s 1 S c g- I oo 7 f Figuresfl3, 14, 15 and 16are explanatory Accordingto the method 0f the present .invention,jthere is first drilled set, e.g., a

row, ofholes spaced apart by a multiple'of the desired unit spacing andthen other holes are'drille'd to fill in these excess spaces until the.desired arrangement of holes-in unit 7 spacing is Obtained. In carryingout the in- I Vention towhat is now considered the best "advantage,succcssivey rows of holes a'aie drilled, each row having. its holesspaced by ing but each hole offset {from I a hole of the first row bytwicethe unit'spacing and lrom afholeof the second' row by unit spacing;N Finally, afour'th row is drilled having the 1 same spacing, theseholes coming half way between the holes of the first and third rows andcompleting a singlerow of singly spaced holes.

' ni sqijs-ie illustrate this method. *i 'i shows the formation ofquadruply' spaced holes 27am a male die bar. Fig. 1a shows 7 the start,and Fig. 15 the completion of the v v second set of holes 27*. Theseare'quadruply v spacedas to each'other, but are .spaced'the unitdistance fromthe first set 27. .Fig. 15 7 shows the start and Fig. 16shows the completion' of'thethird set of holes 27; "lhe'se are quadruplyspaced as to each other but are spaced the unit spacing from the secondset .and'twice unit spacing from the first set. Fig. 1 '6 shows thepartial completion of the fourth set of holes 277*. These are spacedquadruply as to each other but are spaced the unit spacing from thethird set 27. They i5 are'also, as will be apparent, spaced the unitspacing, in the opposite direction, from the V first set 27*; Thisfourth set completes the single'irow of equally spaced holes having the'desired unit spacing, as right hand part of Fig. 16. j I V I This methodmay be conveniently carried outbyflarranging the'bar and adrill in agiveninitial relative position, causing relative'movement between drilland bar. to inappears at the dexone of such elements forward by equaladvance increments, that are a inultipleof unit spacing, drilling a holeforeach, advance increment, repositioning the drill and" bar in:

a second. initial relative position offset from the first initial postion by the distance of unit spacing, again 'causingindexing move ments,with the same advance increment,

again drillinga hole for each advance, and continuing suchrepositioning, indexing; and

i drilling until the complete row of'siiigly, uniformly spaced holes is'drilledi It will now be apparent that the number ofreposition; i v Iings and of drilling cycles will equal the number by; which each advanceis a multiple of'unit spacing.

In carrying out the invei tioi'i according to whatis now consideredthebest practice, the die bar to'zbe-"drilled will becarried by a ji andthejigindexed forward with respect; to the drill. The nitial positioning ofthe increment ,7

bar maybeconveniently accomplished: by

giving'the jig and drill the same relative ini tial position for eachcycle and varying the position-of the bar infthef jig by difilerencesequal tounit spacing, for example, by means of selectivestops.

While the mama described may-be ir ried out in various ways, it mayconveniently be accomplished by the apparatus herein shown and whichforms part of the invention'in its entirety. Y

" Referringflfiirtherto thedrawings, there is provided a drill jig forthework pieceto be drilled, having drilling bushings spaced apart bydistances equalto a multiple of the desired spacing. 'Althoughfcapableof various constructionsfln that here shown as an exam is the 'i coin[rises alon rectan ualr block 4:1 provided with alongitud-inal slot 7for a bar to be drilled. This bar may be', for example, e ther the maledie bar :23, or the female'die bar 28, such as above described.

tone end, the jig 41 has stop means, hereinafterreferred to, forpositioning" the bar lengthwise of the sl ot. f The walls of the slotare machined to acc'urate'fitaiid are provided Hill with grooves 42forchip'clearance and to re- 'ducejthe' areato be ground, Spanning the aslot are a plurality of clamp bars as retained in position by screws44:; At, the center of each clainp bar is a set screw 45 iorclanipingthe bar edgewise in the jig. Located in V spaced recesses 47' in the topof the jig, and

seating on the "work bar when the latter isin place, are a plurality ofdrill bushings 48 having. vertical bores for. guiding and centering adrill e9. The drill bushings are equally spaced and this spacing is amultiple of the unit'spacing of the desiredholes. In thepresentembodiment, the bushings are 1 spaced four times the unitspacing. j

Thereis provided means whereby. either i the work piece or the drill maybe indexed 7 forward by advance increments equal to the f spacing of thedrilling bushings. 'This' may be conveniently accomplished bypositioning the work piece inthe jigand indexing the jig forward withrespect to the drill." 7

Although capable of variousfconstructions, 1 in thathere'shown asan'example,the jig is mounted ina base 51 having a milled groovein'wliich the fits without sideways play but is freely slidable endwise.Betweenthe base and jig is an indexing pin and-liole connection forlocating the jig in its "progres- T3901 thegi'ourthstopa This resultsinafourth row; of holes spaced from those ofthe third stop block 71'?.withafton guefiflf:longer than tongue 73 bythe distance of unit spacing. andFig. 'ZshoWs the fourth; stop block 71 with a tongue 739' longer than;tongue 73 Y by the distance' of unit spacing? The thirdstoprissubstituted. for the second, the die bar positioned in engagement Withtongue 7 3,-

andthe -jig returnedtoinitial position in the base. '1 e The indexingand drilling cy'cleis then repeated, resulting in athird row of holesoff.- set from those 'o'f thesecond rowv byLunit-spacing: and fromthoseof the first'row by twice -unit :spacing. Finally, the indexing anddrillingcycle, is; repeated again, i with the die bar positioned inengagement with the tongue third row in-one directiomandfroin those of Vthe first row in the other direction, by unit spacing. That is, the fourruns of. holes combine: to forma-single row of equallyspaced holes ofthedesired unit spacing. j

t is to be understood th'atthe several rows of multiple: spaced holesneed. not be drilled in the order described. That is, referring to theapparatus described, the stop elements need not beinserted in the ordernamed. They may be used in aziy'order so long as a drilling cycle iisperforined with each stop in' use. e y

In the enibodin ient illustrated, the jig and base provide for onlyone-half the die bar. That isthe holes for onehalf the die bar aredrilled and the'bar is then reversed end-ton end, and the other halfdrilled. For oonvenieiice, the bar is first drilled With the roW ofquadruply spaced holesin one half and then reversed and the analogousroW drilled in the other half, and so on." d in the diebar illustrated,eachhalfof the bar has 107 holes, i. e.,.a n odd number. Consequently,inthe first drilling cycle the hole corresponding tothe last bushing isomitted.

10 make sure that the operator does not neglect to omit this drill, acut oii plug is prol l vided. At the start, this plug is inserted in h tins e b rs may Misp a d w out s otlregistryk l. 7/

In ppar s rr l lige o se 15 spaeed holes in a metal bar, and in conibir;;,

nation, ajig for theibansaid jiggbeing nount plurality oi bushingsJinounted in e above-the ban-.andspaced apartb-y equal'diss tanejes thatarea inul tiple of thedesired spac nigge -base inwhich the 31g sslidable, anniden ing pin carried. thehase, the jig having 7 d edforfsubstantially rectilinear movement, a;

we ef es'i s i i s equ inu b to Y the busl ngsand hav ngth'e samespac1ng,a

support for the base, locatii1gnieans forgiyingthe base apredeterniinedposition on the 2. In apparatus tw c as its fertile ar;-sa diissb si estr ed for substantially rectilinear,rnoveinent, a plurality of drill'bushi-ngs mounted in the 1' above the bar and spa'c'ed apart by equalsupport, and selective stopfbloclzs toi' -engag V I ing: the bar toposition the in. the in e progressively yarying 1 positions; difieringone fronilanother byan amount equal to the desired spacing.

' lyspacedholes in a meta-l bar, and inconibi distances that are amultipleofthedesired it easing,

having a row 'ofindexing holes equalin number to the bushingand havingthe san e'spac ng, a support for the ba ;se,"locating means on thesupport, and appluralityyoij interchangeable stop'locks selectively andindividually attachable to the jig for enga'genient by the bar tozpositionthe same, said stop blocks having progressively-varying barengaging the lastbushing recess sothat a drill for that 1 bushingcan-notb'e made. -F0r the second and succeeding cycles, the plug 75 isremoved.

That is, in one cycle only 26 bushings are utilized but in the otherthreecycles 27 bushings d are used,-thusgiving lOiholes. v 7

*With the method and apparatus described,

drillingz o i the closely spaced holes is effected of strains duetogradual distribution of the holes over the entireylengt'h of the'bar. As

with extreme accuracy. s. The advantages of Q guide bushing forgthedrillare retained and dan'gerot errors due to warpin ot the bar I Iafter drilling is avoided, by uni lorni release v I a result, thepinsand holes of they coinpleinentary die bars register precisely.Moreover, die bars selected at, random are interchangeable, in theperforating .inachine, so

a base in Whichthe jig is slidable, V i ex s P1 tmed brt e' ba e hei sfor. giving the base a predeterminedposition it i

